This training grant provides research training that will allow MD, PhD, and MD/PhD postdoctoral fellows to become independent investigators in the fields of diabetes, obesity, and metabolism. Research training will be provided by a large group of highly-skilled and experienced investigators, from the University of Washington and affiliated institutions, who will serve as preceptors. Based on 1) the continued outstanding success of this program and large numbers of applicants, 2) a major commitment from the University of Washington to create and support a Diabetes and Obesity Center of Excellence in a new research campus, 3) revamped didactic training and oversight and 4) an infusion of new program faculty, including a number of new clinical and translational researchers, we request continued funding of six postdoctoral training positions. In addition, we are requesting six predoctoral positions to support students enrolled in the NIDDK Medical Student Research Program in Diabetes which provides three months of training to eligible medical students. MD candidates will have completed residency training as well as a first, clinical year of fellowship prior to funding by this program. This arrangement allows both MD and PhD fellows to spend a minimum of 80% of their time on research activities while they are supported by this training grant. Fellow applicants will be chosen by the Fellowship Training Executive Committee from a large pool of qualified candidates who apply to the Division of Metabolism, Endocrinology and Nutrition at the University of Washington for their research training. Among the criteria for selection are 1) a strong interest in the fields of diabetes, obesity and glucose or energy metabolism (frequently accompanied by previous research experience), and 2) a demonstrated potential for a successful research career. This program provides trainees with research experience in both basic and clinical aspects of diabetes and obesity, with special emphasis on molecular and cell biology, physiology, and translational research. Research training will be complemented by didactic lectures and seminars that cover diabetes, obesity, glucose homeostasis, energy metabolism and related aspects of endocrinology, with additional coursework in scientific methods, manuscript preparation, grantsmanship, and biomedical ethics. Diabetes and obesity are among our most pressing public health concerns. Despite impressive advances at the basic science level, major unanswered questions regarding the pathogenesis of these disorders continue to limit our capacity to treat them. Effective training fo scientists in diabetes and obesity are therefore fundamental priorities.